1. Field of the invention
The invention relates to a process for removing water and/or other volatile impurities from lubricating oils, particularly as this relates to internal combustion engines, of the kind wherein lubricating oil is, preferably after having been passed through a filter of, for example, fiber material, supplied to a heated evaporation chamber, where the water and/or the other volatile impurities are evaporated and from which escape gases generated during evaporation. The invention further relates to a device for carrying out the aforesaid process.
2. Description of the prior art
It is known that the contaminants in lubricating oils as, for example lubricating oils in internal combustion engines, result in increased wear and reduced efficiency of machines which are lubricated thereby. Solid contaminants, such as dirt, metal particles or the like, can be removed in a simple manner by conventional filters, for example of fiber material, through which is passed the lubricating oil, the solid constituents being thereby retained. Lubricating oils can also contain, however, water and other volatile impurities, which equally give rise to an increased wear of the internal combustion engines on account of forming, for example, an acid which attacks the walls of the pistons and cylinders. For the purpose of removing from lubricating oils these liquid and volatile impurities, it has already been proposed to introduce the lubricating oil to be purified into a heated evaporation chamber, where the lubricating oil is spread over a great surface and is simultaneously heated, so that the liquid or volatile impurities to be removed are evaporated. The gases generated during this evaporation are, in the known device for this purpose, escaping via an exit opening into the atmosphere, and the purified lubricating oil is supplied to be reused, i.e., supplied to the oil pan of an internal combustion engine, for example.
For achieving a complete removal of the liquid or volatile impurities it is necessary that all impurities to be removed evaporate within the evaporation chamber. Such a complete evaporating requires, in the known device, a great spreading surface for the oil as well as a high evaporation temperature. The spreading surface for the oil is, however, limited by the size of the device, which cannot be made large without any limitations due to space requirements. Excessively high evaporating temperatures result in destruction of the lubricating oil. For this reason, it was up until now not possible to achieve a complete removal of the impurities from lubricating oils by means of the known device.